Dynamic fendering system

ABSTRACT

This invention relates to a new and unobvious system for mooring a vessel by means of momentum transfer which induces a current and creates a pressure differential whereby the vessel is drawn toward and held to the mooring facility.

United States Patent Tam [ Sept. 5, 1972 [S4] DYNAMIC FENDERING SYSTEM [72] Inventor: William A. Tam, Westrnont, Ill.

[73] Assignee: Chicago Bridge 8: Iron Company,

Oak Brook, Ill.

[22] Filed: Oct. 15, 1970 [2]] Appl. No.: 80,842

[52] U.S. Cl. ..ll4/230 [51] Int. Cl. ..B63b 21/00 [58] Field of Search ..1 14/230, 231; 61/48, 6, l R

[56] References Cited UNITED STATES PATENTS 3,585,802 6/1971 Frankel ..1l4/230 X Primary ExaminerTrygve M. Blix Attorney-Merriam, Marshall, Shapiro & Klose ABSTRACT This invention relates to a new and unobvious system for mooring a vessel by means of momentum transfer which induces a current and creates a pressure dif ferential whereby the vessel is drawn toward and held to the mooring facility.

7Claims,5DrawingFigures PATENTEDSER 51912 SHEET 1 BF 2 INVENTOR WILLIAM A.TAM fl w 4AM, ,JW?

ATTORNEYS PATENTEDSEP 51912 SHEET 2 BF 2.

FIGZ

DYNAMIC FENDERING SYSTEM BACKGROUND OF THE INVENTION In mooring large vessels such as oil tankers and the like, it is conventional to maneuver the vessel as it approaches the mooring in such a manner that the vessel will be breast moored. The maneuvering of the vessel in some instances is accomplished by means of several tugs which assist in docking the vessel. At the dock or mooring, the vessel is generally held in position by a number of mooring lines or cables with the cables and lines being attached to mooring posts by a dock crew.

Unfortunately, certain disadvantages are attendant with docking employing the use of tugs. Initially, tugs cannot be employed in rough seas so that there are occasions when a ship, because of adverse weather conditions, cannot be moored.

Often, not only must the tugs required for the large vessel be rented or purchased, but a dock crew is also required to handle the various mooring lines and cables utilized to connect and maintain a vessel in a moored condition at a dock. The cables are attached to various support points on the dock and these support points must be structurally designed to withstand the mooring loads.

It would be desirable to have a mooring system, particularly for large vessels, which would eliminate the requirement for tugs as well as the need for cables, winches and dock crews presently necessary to restrain a vessel in its moored position.

SUMMARY OF THE INVENTION In an effort to obviate the disadvantages associated with a tug type mooring system, as well as cables, winches and a dock mooring crew employed with that system, the new and unobvious mooring system disclosed and claimed herein was invented. The mooring system of the present invention involves a mooring facility which utilizes a means of momentum transfer to initially induce a current flow causing a vessel to drift toward the mooring facility and then maintain the mooring by creating a hydrostatic pressure differential on the sides of the vessel.

One such means of momentum transfer involves the utilization of a high pressure nozzle located at the mooring site in association with a particular surface located contiguous to the nozzle to produce what is known as the Coanda effect. The high pressure water stream emanating from the nozzle adheres to the surface causing the water adjacent the mooring facility to be directed downward such that a current flow is induced. This current flow is directed toward the dock and is of a magnitude sufficient to cause the ship, located at a distance from the mooring facility, to drift toward the facility.

As the vessel approaches the mooring facility, the water level between the vessel and the dock is lowered such that the higher water level on the side of the vessel which is furthest from the facility serves to hold the vessel against the dock.

Because water is being pumped out of the nozzles to maintain the difference in water level, the ship is held in a dynamic mooring such that when the ship tends to push toward the dock, it is pushed away by the high pressure water stream, whereas as the ship attempts to move away from the dock, the high pressure water stream serves to maintain the pressure differential thereby drawing the ship back to the dock.

With this type of momentum transfer system, not only is the need for tugs eliminated, but the need for mooring lines and the labor and time usually associated with the mooring of vessels to a dock is also minimized.

Other features and advantages are inherent in the structure claimed or disclosed as will be apparent to those skilled in the art from the foregoing detailed description in conjunction with the accompanying diagrammatic drawings.

DESCRIPTION OF THE DRAWINGS by a high pressure nozzle employed in the mooring system of the present invention.

DETAILED DESCRIPTION OF THE INVENTION Referring to the drawings and more particularly to FIG. 1, there is shown a vessel 10 adjacent the mooring facility of the present invention. The mooring facility comprises dock 20 which utilizes a momentum transfer mooring system. As seen in FIG. 1, dock 20 has several pumping stations 21, 22 located at each end of the dock. The mooring side of dock 20 has two or more fender units such as units 23, 24 attached thereto.

As more clearly seen in FIG. 4, each fender unit includes bumpers 25 which are made of rubber or some other suitable material which will resist the fore and aft surge movements of a ship after the ship has contacted the bumpers.

Surface 27 and particularly portion 29, FIG. 5, thereof is designed to provide what is known as a Coanda surface in order to produce a fluid flow phenomenon that has been called the Coanda effect. This effect has been described as a tendency for a fluid to adhere to and be deflected by a boundary in its flow path. The turning or deflecting of the fluid by the presence of a boundary has been found to increase the momentum of the fluid and thereby the velocity or the entrained mass. For a more detailed description of the Coanda effect, reference can be had to a report entitled Analysis of Thrust and Flow Augmentation of a Coanda Nozzle by E.L. Victory, May 1965, Huyck Research Center, Air Force Contract AF 33 (657) l 1697, Project 7065, pp. l-3. Accordingly, surface 27 is designed such that as water exits from plenum chamber 26, it passes through expansion slot 30 where it will tend to adhere to what is defined herein as a Coanda surface 31 and diffuser surface 32. The surfaces 31 and 32 comprise lower portion 29 of surface 27.

The fluid which exits from expansion slot 30 can be sea water which, by means of one or more pumps 40, is

pumped from the sea or particular body of water,

through pumping stations 21, 22 and then pumped through lines 42, FIG. 1, to plenum chamber 26. The water will exit from expansion slot 30 under high pressure such that the fluid will adhere to the boundary established by the Coanda surface 31 and diffuser surface 33. The water adjacent the high jet stream will also be induced to flow downward with the jet stream adhering to the Coanda surface. Because of this movement of the fluid, the water adjacent the dock or mooring facility is induced to flow in a direction toward the mooring facility. Additionally, as the vessel approaches the facility, the water level between the vessel and the dock is lowered such that the hydrostatic pressure on the side of the vessel furthest from the dock is greater and causes the vessel to move toward the dock.

In a mooring operation, ship would approach along side dock 20 at about a distance of 300-400 feet away from dock 20. Pumps 40 at the mooring facility would then be actuated whereby water would be pumped to chamber 26 where it would exit through expansion slot 30 at a high pressure. As the stream of water exits from slot 30, the stream will adhere to surface 31 and cause the water adjacent the dock to be directed downward. As the operation continues, the forced circulation induces a current which causes the vessel to move sideways toward the dock.

As ship 10 approaches clock 20, the continued forced circulation results in a lowering of the water level Ah between the ship and the dock. As the depressed area becomes less, the hydrostatic pressure increases due to an increase in Ah until as such time that vessel 10 reaches dock 20 as illustrated in FIG. 3.

When vessel 10 is positioned as seen in FIG. 3, Ah is at a maximum and the hydrostatic head of water on side 50 of ship 10 and the opposite side of the fendering units 60 keep ship 10 and dock 20 held tightly together.

With water being pumped out of slots 30 in a jet stream, the Ah is maintained and vessel 10 is held in a dynamic situation such that if the vessel attempts to push toward dock 20, it is held away by the same water which provides a low pressure area if vessel 10 attempts to move away from dock 20.

By placing resilient stand offs or fender 25 at intervals along the units 23, 24, friction loads can be developed between fenders 25 and side 51 of ship 10 which are of sufficient magnitude to resist fore and aft surge movement of ship 10 after it has contacted the fenders 25.

By providing the momentum transfer mooring system of the present invention, not only is the need for tugs obviated but the labor and time necessary to connect mooring lines generally employed in docking a' vessel is also substantially eliminated.

The foregoing detailed description has been given for clearness of understanding only and no unnecessary limitations should be understood therefrom as modifications will be obvious to those skilled in the art.

What is claimed is:

l. Mooring apparatus for docking vessels, said apparatus comprising:

a mooring facility including:

means for providing momentum transfer for creating high pressure fluid forces to force water between a vessel to be moored and said facility downward;

said means including:

at least one expansion slot means for allowing fluid through a slot;

a Coanda surface positionedcontiguous to said slot means and having a curvature sufficient to provide a Coanda effect;

and means for directing fluid through said expansion slot whereby said fluid will adhere to said Coanda surface.

2. Mooring apparatus in accordance with claim 1 wherein said apparatus further includes:

fender means which extend outward from said mooring facility for standing off a vessel to be moored from contacting said facility.

3. Mooring apparatus for docking vessels, said apparatus comprising:

a mooring facility including at least one unit for providing momentum transfer, said unit being attached to a side of said facility for creating high pressure fluid forces to force water between a vessel to be moored and said facility downward;

said unit including a horizontal expansion slot means located along substantially the length of said unit;

pump means for pumping fluid through said slot means;

a surface comprising a bottom portion and a top portion, said portions being separated by said slot means; and,

said bottom portion including a Coanda surface located contiguous to said slot means and having a curvature sufficient to provide a Coanda effect whereby fluid upon exit from said slot means will adhere to said Coanda surface thereby causing water adjacent said facility to move downward.

4. Mooring apparatus in accordance with claim 3 further including:

fender means vertically spaced along substantially the length of said unit and extending outwardly from said surface.

5. Mooring apparatus for docking vessels, said apparatus comprising:

a mooring facility including at least one unit for providing momentum transfer, said unit being attached to a side of said facility for creating high pressure fluid forces to force water between a vessel to be moored and said facility downward;

said unit including a horizontal expansion slot means located along substantially the length of said unit;

pump means for puinping fluid to and through said slot means;

a surface comprising a bottom portion and a top portion separated by said slot means; and,

said bottom portion including a Coanda surface located contiguous to said slot means and having a curvature sufficient to provide a Coanda effect; and,

a plurality of fender means vertically spaced along substantially the length of said unit and extending outwardly from said surface.

6 6. The method of mooring a vessel to a facility 210- and causing water adjacent said facility to be cording to the steps of: directed downward so as to create a hydrostatic actuating pump means located at said facility to pressure differential between the two sides of a cause fluid to be pumped to and through at least vessel to be moored one expansion slot means located adjacent said 5 whereby a vessel to be moored will be directed to facility; said mooring facility. directing said fluid upon exit from said slot means The method of claim 6 f further inclllding the d d b employing a C d surface maintaining of said vessel at said mooring facility solely tiguous to said slot means whereby fluid upon exit by actuatmg 531d P p meansfrom said slot means will adhere to' said surface, 10 

1. Mooring apparatus for docking vessels, said apparatus comprising: a mooring facility including: means for providing momentum transfer for creating high pressure fluid forces to force water between a vessel to be moored and said facility downward; said means including: at least one expansion slot means for allowing fluid through a slot; a Coanda surface positioned contiguous to said slot means and having a curvature sufficient to provide a Coanda effect; and means for directing fluid through said expansion slot whereby said fluid will adhere to said Coanda surface.
 2. Mooring apparatus in accordance with claim 1 wherein said apparatus further includes: fender means which extend outward from said mooring facility for standing off a vessel to be moored from contacting said facility.
 3. Mooring apparatus for docking vessels, said apparatus comprising: a mooring facility including at least one unit for providing momentum transfer, said unit being attached to a side of said facility for creating high pressure fluid forces to force water between a vessel to be moored and said facility downward; said unit including a horizontal expansion slot means located along substantially the length of said unit; pump means for pumping fluid through said slot means; a surface comprising a bottom portion and a top portion, said portions being separated by said slot means; and, said bottom portion including a Coanda surface located contiguous to said slot means and having a curvature sufficient to provide a Coanda effect whereby fluid upon exit from said slot means will adhere to said Coanda surface thereby causing water adjacent said facility to move downward.
 4. Mooring apparatus in accordance with claim 3 further including: fender means vertically spaced along substantially the length of said unit and extending outwArdly from said surface.
 5. Mooring apparatus for docking vessels, said apparatus comprising: a mooring facility including at least one unit for providing momentum transfer, said unit being attached to a side of said facility for creating high pressure fluid forces to force water between a vessel to be moored and said facility downward; said unit including a horizontal expansion slot means located along substantially the length of said unit; pump means for pumping fluid to and through said slot means; a surface comprising a bottom portion and a top portion separated by said slot means; and, said bottom portion including a Coanda surface located contiguous to said slot means and having a curvature sufficient to provide a Coanda effect; and, a plurality of fender means vertically spaced along substantially the length of said unit and extending outwardly from said surface.
 6. The method of mooring a vessel to a facility according to the steps of: actuating pump means located at said facility to cause fluid to be pumped to and through at least one expansion slot means located adjacent said facility; directing said fluid upon exit from said slot means downward by employing a Coanda surface contiguous to said slot means whereby fluid upon exit from said slot means will adhere to said surface, and causing water adjacent said facility to be directed downward so as to create a hydrostatic pressure differential between the two sides of a vessel to be moored whereby a vessel to be moored will be directed to said mooring facility.
 7. The method of claim 6 and further including the maintaining of said vessel at said mooring facility solely by actuating said pump means. 